Cornies was the first president of The Agricultural Improvement Society, an Odessa-based commission that supported German colonists. The organization introduced modern farming practices to the colonies and later extended its reach to education and social life. The commission was sponsored by the Russian government with the hope that the master farming techniques of the Mennonites could be introduced to Jewish, Tatar and Russian villages.[1] The society introduced dryland farming, fertilizer and four-year crop rotation. Planting tobacco and mulberry trees for sericulture were promoted.

Cornies owned a large estate, Jushanlee, a model farm and showplace of south Russia. Crown princesAlexander I and Alexander II as well as other government officials visited the estate. His holdings were expanded by gifts from the government for his services and totaled 100 km2 (25,000 acres) at his death. He owned a large herd of thoroughbred cattle, 8,000 merino sheep and four hundred horses.[1]

Cornies helped also with the immigration and colonisation of Jews. He died at Orloff, a village in the Molotschna colony.